CN115244843A - Power conversion device - Google Patents

Abstract

The power conversion device of the present invention includes: a capacitor for smoothing the direct current power; a plurality of power modules for converting the dc power to ac power; a first substrate, wherein a plurality of the power modules are disposed on the first substrate; a second substrate disposed to face the first substrate; a first channel forming member that forms a channel through which a cooling medium flows together with the surface of the first substrate and the surface of the second substrate; and a second flow channel forming body that forms the flow channel together with the surface of the first substrate, wherein both surfaces of the power module are cooled by the cooling medium.

Description

Power conversion device

Technical Field

The present invention relates to a power conversion device.

Background

In industrial machines and vehicles (for example, automobiles and railway vehicles), from the viewpoint of energy saving and precise driving control, the electric driving and electronic control of a power source have been rapidly advanced. Accordingly, in a power module conventionally used for controlling the power of a power source and a circuit device for performing power conversion (power conversion) using the power module, for example, in the case of an electric vehicle equipped with a power conversion device and a motor, the power conversion device is required to be thin in order to increase the vehicle interior space.

The following patent document 1 is known as a background art of the present application. Patent document 1 discloses a technique for reducing the size of a power conversion device by adopting a configuration in which a power module and a capacitor module of the power conversion device sandwich a cooling water flow path.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2009-44891

Disclosure of Invention

Technical problem to be solved by the invention

With the technique of patent document 1, when the power conversion device is further required to be thin, it is difficult to satisfy the requirement by changing the structure. In view of this, there is a problem of how to provide a thin power conversion device that can achieve both cooling performance and sealing performance in consideration of cooling performance that can efficiently cool the power conversion element, the power smoothing element, the wiring, and the like on the circuit board and sealing performance that prevents the cooling medium flowing inside the flow path from leaking to the outside.

Means for solving the problems

The power conversion device of the present invention includes: a capacitor for smoothing the direct current power; a plurality of power modules for converting the direct current electrical power to alternating current electrical power; a first substrate, wherein a plurality of the power modules are disposed on the first substrate; a second substrate disposed to face the first substrate; a first channel forming member that forms a channel through which a cooling medium flows together with the surface of the first substrate and the surface of the second substrate; and a second flow channel forming body that forms the flow channel together with the surface of the first substrate, wherein both surfaces of the power module are cooled by the cooling medium.

Effects of the invention

The invention can realize the thinning of the power conversion device with both cooling performance and sealing performance.

Drawings

Fig. 1 is a circuit diagram of a power conversion device of the present invention.

Fig. 2 is an explanatory diagram of a power conversion device according to a first embodiment of the present invention.

Fig. 3 is a view of fig. 2 showing the upper portion of the flow channel formation body 27 and the control circuit board mounted thereon.

Fig. 4 is a view of the first circuit board after the flow channel formation body 27 is detached from fig. 2.

Fig. 5 is an explanatory diagram of the flow channel formation member 3 after the first circuit board 1 is detached from fig. 4.

Fig. 6 isbase:Sub>A sectional viewbase:Sub>A-base:Sub>A' of fig. 5.

Fig. 7 is a diagram showing the second circuit board 2.

Fig. 8 is an explanatory view of the flow channel formation body 3 (the back surface in fig. 5) after the second circuit board 2 is detached from fig. 7.

Fig. 9 is a sectional view B-B' of fig. 8.

Fig. 10 is an explanatory diagram of a power conversion device according to a second embodiment of the present invention.

Fig. 11 is an explanatory diagram of the flow channel formation body 27A formed around the power module 4A in fig. 10.

Fig. 12 is an explanatory diagram of the flow channel formation body 3A after the first circuit board 1A is detached from fig. 10.

Fig. 13 is a view of the back surface of the flow channel forming body 3A of fig. 12.

Fig. 14 is an explanatory diagram of a power conversion device according to a third embodiment of the present invention.

Fig. 15 is an explanatory diagram of a power conversion device according to a fourth embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

(Circuit configuration of Power conversion device)

Fig. 1 is a circuit diagram of a power conversion device of the present invention.

The power conversion device converts direct-current power (direct-current power) supplied from a battery mounted in a vehicle into alternating-current power (alternating-current power), smoothes the power with a capacitor connected in parallel, and outputs the smoothed power to a motor. The power conversion device includes three single-arm power modules 4 each including 2 semiconductor elements connected in series.

In each of the single-arm power modules 4, a current flowing through the semiconductor elements of the upper and lower arms is controlled by ON/OFF switching using a control signal input from a signal wiring connected via a gate resistor. The three-phase single-arm power module 4 is connected in parallel to the high-voltage input wiring 106 and the low-voltage input wiring 107, respectively, and is connected to a stator winding of the motor at an intermediate point of the semiconductor elements connected in series.

Further, three-phase single-arm inverters 15 each configured by combining the single-arm power module 4 and the control circuit are connected in parallel to the high-voltage side input wiring 106 and the low-voltage side input wiring 107, and output three-phase ac to the motor by performing ON/OFF control.

The single-arm power module 4 is, for example, a combination of an IGBT (Insulated Gate Bipolar Transistor) and a diode, or a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

(first embodiment)

Fig. 2 is an explanatory diagram of a power conversion device according to a first embodiment of the present invention.

Fig. 2 is a diagram showing the first circuit board 1, in which the power modules 4 of the three phases of the power conversion device are arranged in the circumferential direction, and a flow channel forming body 27 is provided on the circuit board surface thereof, and flow channels through which a cooling medium for cooling the power modules 4 flows are formed.

The first circuit board 1 is fixed to the flow channel formation body 3 which is radially larger than the circuit board, and is fitted and fixed along the circumferential edge. A plurality of screw holes 31 are provided on the circumference to fix the first circuit board 1 and the flow channel formation member 3.

The flow channel forming body 27 forms (is formed to be fitted to) a flow channel, which has through holes 34 in portions where the power modules 4 are arranged, together with the surface of the first circuit board, and is configured to cool the power modules 4 by a cooling medium, which is a fluid flowing through the flow channel forming body 27. That is, the flow channel forming body 27 includes the through hole 34 that functions as a module flow channel portion for individually cooling each of the plurality of power modules 4. The cooling medium flowing through the flow channel forming body 27 flows as indicated by an arrow 21 indicating the flow of the cooling medium, passes through a flow channel hole 25 of a first circuit board described later from the flow channel outlet portion 29, and flows toward the flow channel opening portion 20 of the flow channel forming body 3 (see fig. 5).

The flow channel formation member 27 is fixed to the circuit board surface of the circuit board 1 via the plurality of screw holes 33. The screw holes 33 are fastening holes provided at four corners of each through hole 34 and capable of fixing the flow channel formation body 27, the first circuit board 1, and the flow channel formation body 3 at the same time.

In order to prevent corrosion of the electrical components, the flow channel formation member 27 and the first circuit board 1 are in close contact only around the resin covering the power module 4. The flow channel formation member 27 is formed so as not to contact with the signal control elements, the connection terminals 9c and 9d, and the crimp terminals 10a and 10b, which are located in the signal wiring portion 8, which will be described later.

Fig. 3 is a view of fig. 2 showing the upper portion of the flow channel formation body 27 and the control circuit board 30 mounted thereon. The control circuit board 30 has three control circuits of fig. 1, and outputs control signals of the power modules 4.

The flow channel formation member 27 prevents the fluid flowing inside from leaking to the outside by its upper portion. The flow passage forming body 27 has a flow passage inlet 32 for allowing the cooling medium flowing through the entire power conversion device to flow therein. The plurality of screw holes 33 are also provided in the same positions as described above in the upper portion of the flow channel forming body 27, and are similarly fastening holes that can fix the flow channel forming body 27 to the first circuit board 1 and the flow channel forming body 3 at the same time.

The electrical connections are first explained for the control circuit board 30. The control circuit board 30 is connected to a signal wiring section 8 (see fig. 4) disposed on the first circuit board 1 via a cable and a connector, and includes an integrated circuit (not shown) for generating an output ac waveform by generating a signal of high or low output voltage for a control signal. The integrated circuit includes terminals and wiring on the control circuit board 30 for connection to the overall control device of the power conversion device. This allows the motor to be driven in cooperation with the integrated circuit of the other power conversion device by performing control at the same time.

Next, the configuration of the control circuit board 30 will be explained. In order to prevent the integrated circuit of the control circuit board 30 from reaching a high temperature, the control circuit board 30 is disposed on the surface of the flow path forming body 27 opposite to the surface in contact with the first circuit board 1, and is fixed by screw fastening (fixing by screw fitting) or the like. That is, in the flow channel forming body 27 having a pair of surfaces opposed to each other, one surface is in contact with the first circuit board 1, and the control circuit board 30 is provided on the other surface. Thereby, the control circuit board 30 is indirectly cooled via the flow channel forming body 27. Further, a through hole may be formed in the upper portion of the flow path forming body 27, and the control circuit board 30 may be fitted thereto to directly cool the fluid.

The control circuit board 30 is provided as far as possible from the power module 4 and the crimp terminals 10a and 10b through which the dc power flows, so that the integrated circuit included in the control circuit board 30 does not malfunction due to the influence of the high-frequency voltage and the electrostatic noise and the radiation noise caused by the current during the switching operation.

Fig. 4 is a diagram of the power conversion device in which the flow channel formation member 27 is removed from fig. 2 or 3.

The first circuit board 1 has a multilayer structure in which a high-voltage side and a low-voltage side of a wiring of a voltage input to the power module 4 are separated by an insulator. As described above, the power modules 4 of three phases are provided on the first circuit board 1 of the power conversion apparatus. The single-arm inverter 15 is configured to include the power module 4, the capacitor 5, the signal wiring unit 8, and the output wiring unit 11a. The capacitor 5 is a capacitor for smoothing dc power supplied from the battery, and the plurality of power modules 4 convert the dc power into ac power.

The three-phase single-bridge inverter 15 is electrically connected to each of the second circuit boards 2 described later in fig. 7 disposed to face the first circuit board, and forms a circuit through which a main current for three-phase current conversion flows. The first circuit board 1 is provided with a flow passage hole 25, and the cooling medium flowing out from the flow passage outlet portion 29 of the flow passage forming body 27 is caused to flow through the flow passage hole 25 to a flow passage formed by the flow passage forming body 3 described later.

The electrical connection of the first circuit board 1 (and the electrical connection of the second circuit board 2 described later) will be described. The power module 4 is formed by bonding the upper and lower sides of the semiconductor element with solder and sandwiching copper foil of the semiconductor element, thereby extending the output terminal to the copper foil portion. The power module 4 includes a power conversion element (a combination of an IGBT and a diode, or a MOSFET) for turning on and off the low-voltage side and the output side, and a semiconductor element for turning on and off the high-voltage side and the output side. The high-voltage dc wiring portion 6a is connected to a high-voltage dc wiring portion 6b of the second circuit board 2 shown in fig. 7, which will be described later, via a connection terminal 9 a. The low-voltage dc wiring portion 7a is connected to the low-voltage dc wiring portion 7b of the second circuit board 2 via a connection terminal 9 b. The output wiring portion 11a connected to the power module 4 is connected to the output wiring portion 11a of the second circuit board via the connection terminal 9 e.

A high-voltage dc wiring portion 6c shown in the lower part of the drawing of fig. 4 is connected to the high-voltage dc wiring portion 6b of the second circuit board 2 via a connection terminal 9 c. The high-voltage dc wiring portion 6c is connected to the high-voltage side of the battery via a crimp terminal 10 a. Similarly, the low-voltage dc wiring portion 7c is connected to the low-voltage dc wiring portion 7b of the second circuit board via the connection terminal 9d, and is connected to the low-voltage side of the battery via the crimp terminal 10 b.

When the high-voltage side semiconductor element of the power module 4 is turned on, the high-voltage dc wiring portion 6a is turned on with the output terminal 13, and the output terminal 13 becomes a high-voltage. When the low-voltage side semiconductor element is turned on, the low-voltage dc wiring portion 7a is turned on to an output terminal 13 described later, and the output terminal 13 becomes a low-voltage. At this time, since ripple current is generated, the influence of the ripple current on the battery is suppressed by smoothing the current by the plurality of capacitors 5 between the high-voltage dc wiring section 6a and the low-voltage dc wiring section 7a and the capacitor 14 of the second circuit board 2 connected to the high-voltage dc wiring section 6b and the low-voltage dc wiring section 7b on the second circuit board 2.

Fig. 5 is an explanatory diagram of the flow channel formation body 3 after the first circuit board 1 is detached from fig. 4.

The flow channel forming body 3 is sandwiched between the first circuit board 1 and a second circuit board 2 described later in fig. 7, and is fixed to the respective circuit boards by screwing through a plurality of screw holes 22 provided circumferentially and around a rotation shaft or the like. That is, a flow path through which the cooling medium flows is formed (formed in cooperation) with the surface of the first circuit board 1 and the surface of the second circuit board 2. Further, since the flow channel forming body 3 needs to be in close contact with the circuit boards above and below in the axial direction in order to prevent the cooling medium from leaking to the outside, the flow channel forming body has a concave portion 16a along the flow channel wall, and a member having elasticity is inserted therein to prevent the cooling medium from leaking.

The respective functions of the plurality of through holes of the flow path forming body 3 will be described. The through holes 17 are provided corresponding to the positions of the power modules 4 arranged on the first circuit board 1. With this configuration, the power modules 4 arranged on the first circuit board 1 are cooled not only by the cooling medium flowing through the flow channel forming body 27 but also by the cooling medium flowing through the flow channel forming body 3, so that the power modules 4 can be cooled from both surfaces in the axial direction. The through-hole 23 is a hole through which the connection terminals 9a to 9e pass in order to electrically connect the circuit boards sandwiching the flow path forming body 3 in the axial direction. The through-hole 18 is a through-hole other than the through-hole 17 and the through-hole 23.

The flow path opening portions 19 and 20 of the flow path forming body 3 will be described. The flow passage opening portion 20 is an inlet of the flow passage for allowing the cooling medium flowing through the flow passage forming body 27 to flow into the flow passage in the flow passage forming body 3 through the flow passage outlet portion 29 and the flow passage hole 25. The cooling medium flowing into the flow passage forming body 3 flows as indicated by an arrow 21 through a concave portion 24 provided in the flow passage forming body 3 (details will be described later). The flow passage opening 19 is an outlet for discharging the cooling medium flowing through the flow passage of the flow passage forming body 3 from a flow passage outlet 26 of the second circuit board, which will be described later.

Fig. 6 isbase:Sub>A sectional viewbase:Sub>A-base:Sub>A' of fig. 5.

As described above, the region of the flow channel formation member 3 inside the circumferential edge is sandwiched between the first circuit board 1 and the second circuit board 2 in the vertical direction of the rotation shaft. In addition, in the flow path forming body 3, a concave portion 16b into which a member having elasticity can be inserted is formed also on the side opposite to the side to be fitted to the first circuit board 1 in order to prevent leakage of the cooling medium. This prevents the cooling medium from leaking even when the second circuit board 2 is fitted to the flow channel formation body 3.

Fig. 7 is a diagram showing the second circuit board 2 disposed on the back surfaces of the first circuit board 1 and the flow channel formation body 3 shown in fig. 2 to 4. Here, the detailed description of the electrical connection between the first circuit board 1 and the second circuit board 2 is as described above with reference to fig. 4, and therefore, the description thereof is omitted.

The second circuit board 2 screws the output terminals 13 and the output wiring portions 11b through the fastening holes 12, whereby the outputs of the power modules 4 of the first circuit board 1 are electrically conducted to the output terminals 13.

Further, the second circuit board 2 is provided with the flow passage outlet portion 26, and as described above, the cooling medium flowing from the flow passage forming body 27 to the flow passage opening portion 19 through the flow passage forming body 3 is discharged from the flow passage outlet portion 26 to the outside.

Fig. 8 is an explanatory view of the flow channel formation body 3 (the back surface in fig. 5) after the second circuit board 2 is detached from fig. 7. Here, the same portions of the structure as those already described with reference to fig. 5 are omitted.

The fastening hole 12 is a hole for fastening the second circuit board 2 to the output terminal 13 and the output wiring section 11b by screws. The screw holes 22 are holes for screwing the second circuit board 2 and the flow channel forming body 3 together. By fixing the second circuit board 2 to the flow channel forming body 3, not only the flow channel can be formed, but also the low-voltage dc wiring portion 7b of the second circuit board 2 can be cooled, and the circuit board whose temperature rises due to heat generated at the time of energization can be cooled.

The recess 24 is provided in a part of the flow channel forming body 3 extending from the circumferential edge of the flow channel forming body 3 to the center portion to form the through hole 17. The recesses 24 are provided for passing the cooling medium therethrough, and are formed at 2 positions in the circumferential direction of each through-hole 17. A part of the flow passage forming body 3 functions as a support column which prevents the flow passage of the flow passage forming body 3 from being narrowed by deformation of each circuit board when the first circuit board 1 and the second circuit board 2 are fitted to each other with the flow passage forming body 3 interposed therebetween from above and below in the axial direction. Since a flow path through which the cooling medium passes is formed here, the flow path forming body 3 is provided with a recess 24 in each portion.

Fig. 9 is a sectional view B-B' of fig. 8. In which, unlike fig. 6, the second circuit board 2 is arranged above the drawing and the first circuit board 1 is arranged below the drawing.

The screw hole 22, the recess 16a, and the recess 24 are arranged so as not to overlap with each other in the vertical direction, so that the flow channel forming body 3 can be ensured to a thickness to which it is not deformed. With such a configuration, both the conduction and the stability of the flow channel forming body 3 are ensured.

According to the first embodiment of the present invention described above, the following operational effects can be achieved.

(1) The power conversion device includes: a capacitor 5 for smoothing the dc power; a plurality of power modules 4 for converting the direct-current electric power into alternating-current electric power; a first substrate 1 provided with a plurality of power modules 4; a second substrate 2 disposed opposite to the first substrate 1; a first channel forming member 3 which forms (cooperates with) a channel through which a cooling medium flows together with the surface of the first substrate 1 and the surface of the second substrate 2; and a second flow channel forming body 27 that forms (cooperates with) a flow channel formed on the surface of the first substrate 1, and both front and back surfaces of the power module 4 are cooled by the cooling medium. With this configuration, the power conversion device can be thinned while achieving both cooling performance and sealing performance.

(2) The first flow path forming body 3 of the power conversion device has a plurality of through holes 17 for cooling the plurality of power modules 4, respectively. With this configuration, the flow channel width can be stably maintained while cooling the electric component that generates heat.

(3) The plurality of power modules 4 of the power conversion apparatus are arranged on the substrate in the circumferential direction, and the second flow path forming body 27 has a module flow path portion 34 for individually cooling each of the plurality of power modules 4. With this configuration, the electric component that generates heat can be cooled by the cooling medium flowing through the single continuous flow path.

(4) Including a control circuit board 30 electrically connected to the first substrate 1 of the power conversion apparatus and outputting control signals of the plurality of power modules 4, the second flow path forming body 27 has a pair of faces opposed to each other, one of which is in contact with the first substrate 1, and the control circuit board 30 is provided on the other face. With this structure, the control circuit board 30 can be efficiently cooled without being affected by heat generation.

(5) The first flow path forming body 3 of the power conversion device has a plurality of concave portions 24 for passing the cooling medium. With this configuration, the flow path can be stably maintained and the flow path can be ensured to be conductive.

(second embodiment)

Fig. 10 is an explanatory diagram of a power conversion device according to a second embodiment of the present invention.

The first circuit board 1A is formed for each power module 4A, and similarly, the flow channel formation member 27A is not formed continuously for each power module 4A. That is, each power module 4A on each first circuit board 1A is independently surrounded by the flow channel formation member 27A. In fig. 10, the flow channel formation body 27A located at the upper part of the figure is shown in a state where the upper part thereof is not present, in order to facilitate understanding of the power module 4A provided inside the flow channel formation body 27A. However, in a normal case, the upper portion of the flow channel formation body 27A is covered, similarly to the remaining 2 flow channel formation bodies 27A. Details are described later in fig. 11.

The output terminals 13A of the first circuit board 1A are screwed and fixed to the first circuit board 1A, and extend in the axial direction from the first circuit board 1A to the second circuit board 2 along the rotation axis. The flow passage hole 25A is an inlet through which the fluid enters the power conversion device.

The control circuit board 30A is not provided on the first circuit board 1A but on the flow path formation body 3A. That is, the control circuit board 30A improves the mounting area by concentrating the high-voltage dc wiring portion 6c, the low-voltage dc wiring portion 7c, the connection terminals 9c and 9d, and the crimp terminals 10c and 10d, which are connected to the battery output, at one location. In addition, the second embodiment does not show the second circuit board 2, but the connection with respect to the electric wiring is the same as the first embodiment.

With such a configuration, the control circuit board 30A can be provided at a lower position than the position provided on the flow path forming body 27 in the first embodiment in the height above and below the power conversion device in the axial direction, and the thickness of the entire power conversion device can be reduced.

Fig. 11 is an explanatory diagram of the flow channel formation member 27A formed in the power module 4A in fig. 10. The inside of any flow channel formation member 27A in fig. 10 has the same configuration.

As shown in fig. 11, a flow channel formation member 27A is formed around the power module 4A. This is achieved by forming the flow channel formation body 27A so as to cover the periphery of the resin applied on the circuit board so as to surround the power module 4A.

The signal wiring portion 8 is provided around the flow channel forming body 27A, while the output wiring portion 11c is provided around the plurality of through holes 36a and 36b located inside the flow channel forming body 27A and extends toward the center of the rotation axis in the radial direction. The output wiring portion 11c is provided with a fastening hole 43, and is fastened and electrically connected to the output terminal 13A located below the fastening hole by screwing.

The cooling medium flows inside the flow passage forming body 27A, and the cooling medium having flowed through the flow passage forming body 3A described later flows into the flow passage forming body 27A from the through hole 36a, flows through the flow passages partitioned by the baffle plate 42 as indicated by an arrow 21, and flows into the flow passage forming body 3A again from the through hole 36b (described later in detail). That is, the first circuit board 1A has a plurality of through holes for cooling the power modules 4A.

Fig. 12 is an explanatory diagram of the flow channel formation body 3A after the first circuit board 1A is detached from fig. 10.

Since the flow channel formation body 27 described in the first embodiment is not provided, the thickness of the flow channel formation body 3A in the direction of the paper surface can be increased. Therefore, the width of the flow path in fig. 13 described later can be increased, or the width of the flow path can be narrowed near the through hole 37 overlapping with the power module 4A.

This makes it possible to adjust the flow rate by the flow channel formation body 3A and narrow the flow channel at a specific portion, so that the cooling of the circuit board is limited to the wiring portion where heat is present, the flow channel is narrowed, the flow rate is increased, and the wiring is easily cooled efficiently to reduce the temperature of the circuit board. Further, since the thickness of the flow channel formation member 3A is increased, the screw hole can be provided deeper in the flow channel formation member 3A than in the first embodiment.

The plurality of through holes of the flow path forming body 3A will be described. The plurality of through holes 37 are formed to cool the power module 4A of fig. 10 and 11 with the cooling medium from both the upper and lower surfaces in the axial direction. The baffle 38 provided to partition the plurality of through holes 37 is used to control the flow of the cooling medium to form a desired flow path. The flow of the cooling medium (arrows of 21a to 21c, 21e, 21f, 21h, 21 i) will be described in detail in the description of fig. 13.

The through holes 39a to 39c allow connection terminals for connecting the first circuit board 1A and the second circuit board 2 to pass therethrough, and the through hole 40 allows connection terminals for connecting a battery to pass therethrough.

A member having elasticity is inserted into the concave portion 16a so that the cooling medium does not leak to the outside when the first circuit board 1A is fixed to the flow channel forming body 3A.

Fig. 13 is an explanatory view of the rear surface of the flow channel forming body 3A of fig. 12. The second circuit board 2 fitted and fixed to the surface of the flow channel formation body 3A from the axial direction is not shown.

The flow pattern of the cooling medium flowing through the flow passage forming body 3A and the flow passage forming body 27A will be described with reference to fig. 11 to 13.

First, the cooling medium flowing from the flow passage hole 25A shown in fig. 11 and 12 flows from the flow passage inlet portion 32 shown in fig. 13 as indicated by an arrow 21 a. Subsequently, the cooling medium flows into the through-hole 41a, and flows as indicated by an arrow 21b of the through-hole 37 in fig. 12. At this time, the cooling medium directly cools the surface of the flow channel formation body 3A side in the power module 4A.

Thereafter, the cooling medium flows into the surface of the first circuit board 1A on the opposite side thereof through the through-hole 36a of fig. 11 provided in the first circuit board 1A, and flows through the flow channel formed by the flow channel forming body 27A and the baffle plate 42 as indicated by an arrow 21 on the surface of the power module 4A. With this configuration, the power module 4A can be cooled also from the surface opposite to the surface on the side of the flow channel formation body 3A, and therefore the power module 4A can be cooled from both front and back surfaces.

Then, the cooling medium flows through the through-hole 36b of fig. 11 provided in the first circuit board 1A, flows into the through-hole 37 of fig. 12 again, flows as indicated by an arrow 21c, flows from the through-hole 41b to the back surface of the cooling block 3A, and flows as indicated by an arrow 21 d.

Similarly, the cooling medium flows into the through-hole 41c, then flows as indicated by an arrow 21e of the through-hole 37 in fig. 12, and flows from the through-hole 36a in fig. 11 into the surface of the power module 4A and the flow channel forming body 27A. Then, the flow proceeds from the through hole 36b as indicated by an arrow 21f in fig. 12, and further proceeds from the through hole 41d as indicated by an arrow 21 g.

Similarly, in the cooling of the other power module 4A, the cooling medium flows in the order of arrow 21g, through hole 41e, arrow 21h, through hole 36a, arrow 21 (fig. 11), through hole 36b, arrow 21i, through hole 41f, and arrow 21 j.

The cooling medium advances as indicated by an arrow 21j and is then discharged from a flow path outlet 26 provided on the second circuit board 2, not shown.

According to the second embodiment of the present invention described above, the following operational effects can be achieved.

(6) The surface of the first substrate 1A of the power converter has a plurality of through holes 36a and 36b for cooling the power module 4A. With this configuration, the power module 4A is cooled, and the power conversion device can be made thinner.

(7) The plurality of power modules 4A of the power conversion apparatus are arranged on the substrate in the circumferential direction, and the second flow path forming body 27A is provided separately for each of the plurality of power modules 4A. This structure contributes to the reduction in thickness of the power conversion device.

(third embodiment)

Fig. 14 is an explanatory diagram of a motor including a power conversion device according to a third embodiment of the present invention.

Fig. 14 shows a structure of a motor, and illustrates an outer rotor type motor. The electric motor includes a rotor 45 and a stator case 46, and the flow passage forming body 3B and the flow passage forming body 27B are provided on a surface of the stator case 46 opposite to a side where the rotor 45 is located.

A power conversion device (not shown) is present on the surface of the passage forming body 27B that contacts the stator, and the output terminal 13B is connected to the tip of the output wiring portion led out therefrom. The output terminal 13B is connected to a wire drawn from the tip of the stator coil 44 from the inside of the stator case 46 of the motor, thereby forming a three-phase ac circuit with the stator coil 44 as a load. A three-phase ac current flows through the stator coil 44 to generate a rotating magnetic field, and the rotor 45 positioned outside the stator is rotated in accordance with the rotating magnetic field.

The capacitor 14B is disposed so as to enter the inside of the stator case 46 on the radially inner side of the axis of the stator, and the space between the stator and the axis is effectively used in the radial direction. In addition, the output current sensor 47, the stator flow path inlet 48, and the stator flow path outlet 49 are provided radially inside the stator coil 44, taking into consideration the same advantage.

A flow passage outlet (not shown) of the power converter is connected to the flow passage inlet 48 of the stator, and the cooling medium is made to flow as indicated by arrow 21B and discharged from the flow passage outlet 49 of the flow passage forming body 3B. This makes it possible to make the cooling medium flowing through the motor and the power conversion device the same, and to cool the devices that generate heat at the same time.

The power conversion device may be disposed between the stator and the rotor, for example, by concentrating the positions of the inlet and outlet of the cooling medium flow path, the connection position of the output wiring unit and the crimp terminal, and the connection position of the connection terminal of the control signal wiring on the same surface of the circuit board.

(fourth embodiment)

Fig. 15 is an explanatory diagram of a power conversion device according to a fourth embodiment of the present invention.

Fig. 15 is different from the third embodiment of fig. 14 in that the rotor 45 is disposed on the surface of the stator on the flow channel forming bodies 3C and 27C side. The stator flow passage inlet portion 48C is provided as a flow passage outlet of the cooling medium for cooling the stator coil 44, and is a flow passage extending to the flow passage inlet portion (not shown) of the flow passage forming body 3C. Thereby, the cooling medium flows as indicated by arrow 21C, flows into the power conversion device, and flows from the channel outlet portion (not shown) of the channel forming body 3C to the channel outlet portion 50 as indicated by arrow 21C and is discharged.

Further, the dc power input wirings 52a and 52b provided inside the stator coil are connected to input terminals provided on a second circuit board (not shown) in the gap between the flow path forming body 3C and the stator housing 46, and are electrically connected to wirings of the second circuit board. In this case, the connection terminal having the function of electrically connecting the circuit boards illustrated in the first and second embodiments is not required, and the signal input wiring 51 is connected to the control circuit instead, whereby the power and the control signal from the outside can be input.

The above embodiments are merely examples, and are not limited to the specific configurations described so long as the features of the invention are not lost. For example, a part of the structure of the embodiment can be replaced with a structure that is common knowledge of those skilled in the art. Further, a structure common to the technical knowledge of those skilled in the art may be added to the structure of the embodiment. That is, in the present invention, a part of the configurations of the embodiments of the present specification may be deleted, replaced with another configuration, or another configuration may be added without departing from the technical spirit of the present invention, and such a configuration is also included in the scope of the present invention.

Description of the reference numerals

1. 1A first circuit board

2. Second circuit board

3. 3A-3C, 27A flow channel formation member

4. Power module

5. 14 capacitor

12. 43 fastening hole

15. Single bridge arm inverter

16a, 16b, 24 recess

17. 18, 23, 34, 36, 37, 40, 41a, 41b through hole

19. 20 flow passage opening part

20. 32, 48 flow inlet part

21. 21a to 21k, 21B, and 21C are arrows indicating the flow of the cooling medium (fluid)

22. 31, 33 screw holes

25. 25A channel hole

26. 29, 49, 50 flow passage outlet part

30. 30A control circuit board

38. 42 baffle

44. Stator coil

45. Rotor

46. Stator housing

Claims (7)

1. A power conversion apparatus, characterized by comprising:

a capacitor for smoothing the direct current power;

a plurality of power modules for converting the direct current electrical power to alternating current electrical power;

a first substrate, wherein a plurality of the power modules are disposed on the first substrate;

a second substrate disposed to face the first substrate;

a first channel forming member that forms a channel through which a cooling medium flows together with the surface of the first substrate and the surface of the second substrate; and

a second channel forming body which forms the channel together with the surface of the first substrate,

wherein both sides of the power module are cooled by the cooling medium.

2. The power conversion apparatus according to claim 1, characterized in that:

the first flow path forming body has a plurality of through holes for cooling the plurality of power modules, respectively.

3. The power conversion apparatus according to claim 1, characterized in that:

the plurality of power modules are arranged on the substrate in the circumferential direction;

the second flow channel forming body includes a module flow channel portion for individually cooling each of the plurality of power modules.

4. The power conversion apparatus according to claim 1, characterized in that:

comprises a control circuit board electrically connected with the first substrate and used for outputting control signals of a plurality of power modules,

the second flow path forming body has a pair of faces opposed to each other, one of the faces being in contact with the first substrate, and the control circuit board being provided on the other face.

5. The power conversion apparatus according to claim 1, characterized in that:

the first flow path forming body has a plurality of concave portions for passing the cooling medium therethrough.

6. The power conversion apparatus according to claim 1, characterized in that:

the first substrate has a plurality of through holes for cooling the power module.

7. The power conversion apparatus according to claim 6, characterized in that:

the plurality of power modules are arranged on the substrate in the circumferential direction,

the second flow path forming body is provided separately for each of the plurality of power modules.

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